The present invention relates to a solid-liquid separator for separating liquid from a material for treatment that contains a large volume of liquid.
Solid-liquid separators that separate liquid from a material for treatment containing a large volume of liquid are commonly known and described in, for example, JP 7-10440. Material treated by such a solid-liquid separator include, for example, organic sludge such as wastewater from food processing, sewage, or wastewater from pig farms; inorganic sludge such as cutting lubricant containing chips, waste fluid from plating, ink waste fluid, pigment waste fluid and paint waste fluid; or else chopped vegetable scraps and fruit skins, bran, and foodstuff remains.
A conventional solid-liquid separator has a screw that extends through a tubular body, material for treatment that has flowed into the tubular body from an inlet opening on one end in the axial direction of the tubular body is transported by the rotating screw; the liquid separated from the material at this time, that is, the effluent, is discharged from the effluent discharge gaps in the tubular body, and the material from which the liquid portion has been reduced is discharged through the outlet opening at the other end in the axial direction of the tubular body.
However, with such a conventional solid-liquid separator, when a material that can easily lose its fluidity is subject to dewatering, such material, having undergone liquid separation within a tubular body, has reduced fluidity, and adheres to the surface of the screw and begins to rotate unitarily with the screw. If this happens, the material is not transported by the screw, and there is the danger that the tubular body interior will become clogged. Particularly in the case of inorganic sludge and chopped vegetables scraps, fruit rinds, or bran and foodstuff remains, the tubular body interior can easily become clogged.